A system for controlling the light output of a monochromator by any simple function and for temporally modulating the intensity

This paper describes an apparatus that controls the output of a monochromator so that the energies in each waveband can be equated according to any desired function. A photocell monitors the light from the monochromator and provides a feedback to the power supply driving the lamp. A function generatoris mechanically linked to the monochromator’s wavelength drive and provides the function for correcting the output spectrum. Once set, the light output remains constant even if the bulb ages or is replaced. If desired, a sinusoidalripple of variable frequency and amplitude can be imposed on the mean intensity of the light.